Geomatics
Formula for area of curved boundaries with one straight side: d = intervals between perpendiculars h_0 = first perpendicular h_n = last perpendicular h_1 through h_n-1 = intermediate perpendiculars
Area = (h_0/2 + sum of h_1 to h_n-1 + h_n/2) x d (trapezoidal rule)
Formula for area of a trapezoid:
Area = (side 1 + side 2) x height / 2
Formula for area of all boundaries curved with zero end perpendiculars (oval):
Area = (sum h_1 to h_n-1) xd
Formula for area of a triangle: (in square feet and acres)
Area = base x height/2 Area = bxh / 2x43560
Formula for area of a long narrow curved area:
Area = length of centerline x average width
Formula for area of a rectangle: (in square feet and acres)
Area = width x length Area = w x l / 43560
Taping on sloping land is more difficult compared to taping on flat or level land. Taping is to be considered a horizontal line. Sloping land is often measured along the soil surface followed by entering a correction factor. The correction factor is determined by the ___________.
% slope of the land
Permissible error (E) = (2 methods)
0.02 x sqrt(# of setups) sqrt(traverse length/100) x 0.014
Fractions of a foot are typically recorded as ______.
0.1 and 0.01 feet
Manipulating units of measure is key to calculating area. Which of the following is NOT a common unit of measure? - 1 rod = 16.5 ft - 1 chain = 88 ft - 1 meter = 3.28 ft
1 chain = 88 ft
Units of measure: 1 rod = how many feet? 1 chain = how many feet? rods? 1 acre = how many square feet? square rods? square chains? 1 hectare = how many acres?
1 rod = 16.5 ft 1 chain = 66 ft, 4 rods 1 acre = 43560 sqft, 160 sq rods, 10 sq chains 1 hectare = 2.471 acres
Tape measures used for agricultural survyeing are often ____ feet in length.
100
When distance is given in stations, it indicates the number of _________.
100 foot lengths
Taping pins are used during surveying to assist the survey team in measuring long distances. The pins are stored on a ring. How many pins are located on a complete set?
11
Referring to the black segments on a self-reading target rod, some segments display a pointed, angular end. The pointed end of the black segment represents _________.
5 one-hundreths of a foot mark
When measuring fractional tape lengths, use a tape with graduations located between the "0" and "1" ft mark. If the rear tape person holds the tape even with the 56 foot mark and the head tape person reads 0.15 at the finish point, the distance measured is ______ feet.
55.85
Early surveyors in the US have used different equipment including a wire chain. The wire chain is called "Gunter's Chain" and was ___ feet long.
66
What percent is 1 sigma away from the mean? 2 sigma? 3 sigma?
68%, 95%, 99%
A surveying crew, taping on a uniform 20% slope, is directed to mark a spot 75 feet from the top of the slope along a horizontal plane. How far, along the soil surface, should the survey crew measure? The correction factor for a 20% slope = 2.0.
77.0 feet
Calculate the following distance: The rear tape person is holding 7 pins, one pin is in the ground, and the head tape person is holding 3 pins. The tape measure used has the first foot, between 0 and the 1 ft mark, graduated to 1/100's of a foot. The rear tape person is holding the 79 ft mark even with the pin and the head tape person reads 0.63 at the finish point. What is the distance of the traverse?
778.27 ft
Permissible error ___ actual error (misclosure) or adjustments are needed.
>
Height of Instrument -
the line of sight through the instrument
How does a slope correction factor work? (5% with correction factor of 0.1)
the taping crew must measure 100.1 feet along the surface of the land to measure 100 feet of the horizontal distance on a uniform 5% slop
The head tape person has which end of the tape?
the zero end
Why should open traverses be avoided?
there is no method for checking errors
When attaching the instrument to the tripod __________.
turn the instrument base with one hand while holding the instrument with the other hand
Plane surveying -
type of surveying in which the surface of the earth is considered to be a plane for all x and y dimensions
Use of range poles:
used for long taping exercises, used to keep the tape in a straight line, especially useful on rolling terrain where it is difficult to see the end of the land being measured
Control survey (CS) -
used to reference both preliminary and layout surveys, establish a network of horizontal and vertical monuments to serve as a reference for imitating other surveys
The Table of Contents should contain a brief description and page reference for each survey exercise. T/F
True, and the location, date and space for a grade
Steel tapes should be cleaned with _________.
a dry cloth
What is an approved turning point?
a hatchet imbedded in the ground
Stadia -
a pair of fixed horizontal lines in a survey instrument used to determine distance
Benchmark -
a permanent point of known or assumed elevation
HI =
Elevation + BS
A field notebook should contain a Table of Contents at the "end" of the field notebook to avoid wasting pages. T/F
False
After leaving the worksite the survey team should check the field notes for accuracy. T/F
False
Keeping field notes is NOT considered a very important aspect of survey work. T/F
False
Sketches do not contain dimensions or stations. T/F
False
A set of survey field notes is signed by the data recorder in the upper margin of the left page. T/F
False, the lower corner of the righthand page
The names of the survey party are listed in the margin of the tabulation page. T/F
False, the margin of the sketch page
When leveling a survey instrument with three leveling screws, the leveling screws must be located directly over the tripod legs. T/F
False, they must be located parallel to two leveling screws
Weather information is located in the upper right corner of the left (tabulation) page. T/F
False, upper left corner of the right (sketch) page
Marking a right angle to a line requires the survey crew to use a pair of arcs that radiate from a common base line. T/F
True
The function of a turning point is to create a location place for the target rod that will not change elevation when the target rod is rotated for a back sight reading. T/F
True
What can help keep a steel tape in good condition?
a coating of oil or wax to prevent rusting
What is GIS?
a computerized database management system designed to manage spatial data, data is defined by location and multiple attributes
What is GPS?
a constellation of at least 24 US satellites that provides worldwide accurate position coordinates
Pacing -
a crude and rough method of measuring distances, because it is quick, it can be used to detect large errors when measuring with another method
Tachymetry -
a method of measuring using an observation on a rod equipped with stadia, there are three crosshairs in the instrument, a reading is taken using the upper and lower cross hairs, then the distance is the difference between the upper and lower readings
Chaining -
a method of measuring with an iron chain-like device containing 100 links and measuring 66 feet long, today its a term that represents the process of measuring distance with a tape measure
Differential leveling -
a method to determine the difference in elevation between two or more points
Odometry -
a simple method of measuring distances by counting the number of revolutions of a wheel with a known circumference
Turning point -
a solid location, usually marked by a temporary stake, on which a foresight is taken, to which the instrument is moved, and from which a backsight is taken to determine a new height of instrument
Existing angles can be measured using a tape measure, survey pins and _______________________.
a trigonometric sine table
Obtaining correct measurements, readings, and recording them correctly in a set of field notes is a description of ______________.
accuracy
The most important fact in a quality set of field notes is the ___________.
accuracy of the data
The unit used to measure large land areas in the US is the ________.
acre
How to read a tape graduated one foot before the 0 mark (101 foot tape)?
add distance from zero to finish point to distance at last pin
The tripod legs should be pushed into the soil, by stepping on a foot pedal to __________.
adjust instrument height, anchor the instrument, level the instrument
Area is recorded as the number of__________. - hectares - square feet - acres
all of these
Modern methods of measuring linear distance include which of the following? - electronic devices - odometry - pacing
all of these
Which of the following is an acceptable method of preventing damage to a survey instrument when being transported to a new worksite? - detach from tripod - tighten all adjusting screws - store instrument in the instrument box
all of these
Which of the following is required for taping? - ring with 11 pins - field notebook - steel or nylon tape
all of these
Which of the following may result in taping errors? - improper allignment of the tape - reading wrong numbers - pin counting errors
all of these
Taping -
also called chaining, is the most common method of measuring horizontal distances, most tapes used for measuring land are 100 ft in length, full tape length = station (357.65 = 3 + 57.65)
The face of a target rod, which contains the numbers, should be directed ____________.
at the instrument
When reading the target rod with a survey instrument, the operator checks the level _________.
before and after each reading
When using a steel tape, care must be taken to avoid damaging the tape. If a steel tape is allowed to kink, it may __________.
break
Calculating area of quadrangles without parallel sides:
break shape into multiple shapes, 2 triangles work for this shape
When the operator is moving in the area of the survey instrument, care should be used to avoid accidental contact with the tripod legs. Contact with the tripod legs _________.
can change the instrument level adjustment
An alternate method, without using a tape measure, of marking a perpendicular is accomplished by a method called the ________.
chord method
3 GPS Segments:
control - brain, DoD space - satellites user - civil and military
The purpose of the leveling procedure is to ___________.
create a level line of sight
What is error?
difference between measured/observed and true value
The rear tape person directs the head tape person left or right, using hand signals, to allign the tape with the ________.
end point
Leveling: Actual Error = (misclosure)
ending elevation - beginning elevation
Accuracy Ratio =
error of closure / distance measured
When reading the values associated with the black segments on a self-reading target rod, the top of the black segments always represents ___ values.
even
Which of the following is required to view the target rod through the telescope? - focusing the instrument - leveling the telescope - pacing the distance to the target rod
focusing the instrument
The large red numbers on a self-reading target rod represent ______.
foot marks
When using a target rod on sloping land, the target rod must be _________.
fully extended
Preliminary survey (PS) -
gather geospatial data to locate physical features for plotting to scale on a map
2 Types of data stored in a GIS:
graphic and non-graphic
Elevation -
height of land above sea level
Which of the following is NOT an error when taping? - holding 15 lbs pull on the tape - not using a plumb bob on sloping land - recording wrong numbers
holding 15 lbs pull on the tape
What angles do surveyors measure?
horizontal and vertical
What distance do surveyors measure?
horizontal and vertical
Rounding off Numbers: Sig Figs How to round when the digit to be dropped is 5?
increase by 1 if odd, leave unchanged if even
Layout survey (LS) -
involve marking on the ground feature shown on a design plan
Target rods should be used with care to prevent damage to the _________.
latching mechanism, face with numbers, alignment stop
What positions do surveyors measure?
latitude and longitude northing and easting x, y and z
Which of the following reduces accuracy of a survey? - adjusting the focus knob - setting or releasing the brake knob - leaning on the instrument or leaning on the tripod legs while taking a reading
leaning on the instrument or leaning on the tripod legs while taking a reading
When leveling the telescope on a survey instrument the leveling screws are turned using the thumb and index finger on each hand. The leveling bubble is moved by turning the screws under the telescope, moving one thumb to the left and the other to the right (opposite directions). If the operator is facing the instrument, the bubble on the telescope level will move in the same direction as which thumb?
left
Calculating the distance between two points using crosshairs in an instrument when the distance between the crosshairs is known is called __________.
leveling
When preparing to use the tripod level, the legs of the tripod should be pushed firmly into the soil before __________.
leveling the instrument
Which of the following is done to keep the tape in a straight line? - use the slope correction table - use only steel tapes that do not bend - lift the tape so gravity pulls the tape into a straight line
lift the tape so gravity pulls the tape into a straight line
When the instrument is stored in the instrument box, the leveling screws are _____________.
loose to allow movement
The first step when moving the tripod to a new location in a survey traverse is to _________.
loosen the clamp/wing nuts on each tripod leg
The rod person should lean the target rod forward and backward slowly to acquire the ________.
lowest target reading, shortest distance to the ground, most accurate rod reading
Theodolite -
measuring horizontal and vertical angles and for establishing linear and curved alignments in the field
The target rod is held with the ________ end on the turning point.
metal foot, zero, bottom
Adjustment procedure for leveling:
misclosure / number of setups of instrument (adjustment will be the opposite sign of the misclosure)
A method of marking a perpendicular uses a triangle with sides that are _________.
multiplies of 3, 4, and 5
Gunter's chain was a handy tool because 10 square chians equaled ________.
one acre
Instrument levels all have essentially the same parts. Which of the following is NOT an instrument part? - telescope - leveling plate - refracting prism - leveling device (screws)
refracting prism
After completing a survey traverse, the instrument should be packed in its storage case before leaving the site. The first step to repack the instrument is to ___________.
remove the sunshade and install the lens cap
A system used to reduce entering incorrect values includes __________.
repeating values orally
Formula for area of a triangle: (measure all sides)
s = (a+b+c)/2 Area = sqrt(s(s-a)(s-b)(s-c))
It is a common practice for the legs of a tripod to be strapped together for _________.
safe transport and storage
When erecting a perpendicular using the 3-4-5 method, a survey crew creates two arcs that should cross. If the arcs do NOT intersect the survey crew should _________.
select different tape measure values
When crossing a fence with a survey instrument ____________.
set the instrument on the opposite side of the fence before climbing the fence
How do you clean a nylon tape?
soap and water
When removing a tripod cap ring, the ring should be __________.
stored in the instrument box
How to read a tape graduated between 0 and the 1 foot mark?
subtract distance from zero to finish point from distance at last pin
Leveling: Math error check =
sum of BS - sum of FS
Systematics error vs Random error:
systemic errors can be determined random errors can't be accounted for and are beyond surveyors control, use probability with these errors
To level a survey instrument the ________ must be over any two leveling screws.
telescope
When handling a survey instrument, lift the instrument by the ________.
telescope frame
When taping, the head tape person carries _______.
the "0" end of the tape
How do we determine the true value?
the most probable value is the true value average all measured values
The rod person should hold the target rod lightly, balancing the rod on a vertical position. If the target rod is not held vertical, readings will be ____________.
too high and inaccurate
Which of the following shapes is a four-sided shape with only two parallel sides? - trapezoid - rectangle - quadrilateral
trapezoid
When setting up a tripod for use, adjust the legs so the __________.
tripod head is nearly level, instrument will be stable, tripod head is approxiamtely shoulder level
Which of the following is included in the title? What page does this go on?
type of survey, name of property or area, legal description goes on the left (tabulation) page
Geodetic surveying -
type of surveying in which the earth is considered to be ellipsoidal for x and y dimensions
What equipment is used to assure the tape is in a straight line during a taping exercise?
range poles
Peg Test:
First setup: level midway and rod readings taken - difference is true diff Second setup: level moved closer to A and rod readings taken - difference is apparent diff Error = true diff - app diff Collimation correction (C factor) = error/traverse length
GNSS -
Global Navigation Satellite System
GPS -
Global Positioning System
The rod person should hold the target rod by placing his or her fingers _________.
only on the edges of the target rod
The method of measuring distance by counting the number of steps an individual takes between two points is called _______.
pacing
While repacking a survey instrument, after placing the instrument into the storage case ________.
place the ring or cap on the tripod
The procedure for taping starts with _________.
placing a survey pin at the starting location
A survey team measuring distance on sloping land may use which of the following tools to accurately determine the location of the survey pins?
plumb bob
When the last distance to be measured is a fraction of the tape length, the distance is called a ______________.
plus station
Use of a plumb bob:
provides the chaining crew with a straight line from the tape, held level, to the ground
The shape that contains no parallel sides is called a ______________.
quadrilateral
A field notebook page is described as ___________.
both a tabulation and a sketch page
Formula for % slope:
% slope = difference in elevation / distance between points x 100
Measuring angles with steel tape: 3-4-5 method
- lay out a 40 unit long line (AB) - swing an arc of 50 unit long toward point C (AC) - swing an arc of 30 unit long toward C (BC) - where the arcs intersect is point C
Measuring angles with steel tape: chord method
- measure equal distances from base of perpendicular - swing arcs from A and B the same distance to meet back up with the perpendicular
Most non-rectangular fields, plots, and areas can be divided into geometric shapes. What are the geometric shapes used to calculate agricultural area?
- rectangles - triangles - trapezoids - quadrilaterals without parallel sides - curved boundaries with a straight side - all boundaries curved - long narrow curved areas
What do the following symbols mean? - circle w line through it - square w line through it - ⊼ - RT or RC - HT or HC
- rod person - note keeper - instrument operator - rear tape person - head tape person
Calculating area of plots, fields, or gardens is often performed with a tape measure combined with application of mathematical rules. The units of measure often vary, with the area of one acre equal to _________. (rods^2, ft^2, hectares)
160 rods^2 43,560 ft^2 0.404 hectares
A taping crew is measuring along a traverse over 100 feet long using a 100 foot tape. The rear tape person has three pins in hand; the head tape person holds 7 pins and one pin is in the ground. The crew has traveled _______ feet.
300
When taping on a uniform slope of 12%, what is the actual, horizontal distance, if the distance measured along the soil surface is 329 feet? The correction factor for a 12% slope = 0.7.
328.3 feet
Formula for area of all boundaries curved: d = intervals between perpendiculars h_0 = first perpendicular h_n = last perpendicular h_1 through h_n-1 = intermediate perpendiculars
Area = (h_0/2 + sum of h_1 to h_n-1 + h_n/2) x d (trapezoidal rule)
Formula for area of a triangle: (two sides and the included angle)
Area = side AB x side AC x sinA /2
Survey notes data may be recorded on a field worksheet and then re-entered into a field notebook. T/F
False
The number of digits to the left of the decimal represents the degree of accuracy while completing a survey traverse. T/F
False, the decimals to the right represent accuracy
What symbol represents the head tape person?
HC
Elevation =
HI - FS
The standard form for a set of field notes used while taping, by a survey crew, is to title the columns on the tabulation page as ____________.
Sta. Fwd. Dist. Back Dist. Mean Error Ratio
Break Chaing Notebook Setup and Calculations:
Station, forward distance, backward distance, mean, error, accuracy ratio mean = avg of distances error = |(mean - fwd)| + |(mean - back)| accuracy ratio = error/mean, denominator to the nearest hundred
What do surveyors do?
Take and analyze measurements
When taping, the field notebook entries should be entered according to a standard form. T/F
True
A completed set of taping field notes is signed by the head tape person, when the taping is completed by a crew of two. T/F
True
A good practice when recording taping data to reduce errors and improve accuracy is to repeat the values aloud before entering the data into the field notebook. T/F
True
A sequential pattern used to collect and record surveying data is recommended. T/F
True
A taping crew typically consists of a head tape person and a rear tape person with a third person acting as the opitonal note keeper. T/F
True
Always carry the instrument in front of you when passing through brush, timbered areas, or inside a building. T/F
True
Arranging survey data on the field page is often helpful to permit the reader to understand the data. T/F
True
DO NOT crowd notes, allow enough space to enter data clearly. T/F
True
Do no erase in a data portion of a field notebook; corrections are made by drawing a line through the incorrect data and entering the correct data above the error. T/F
True
Historically, surveying was used to mark land boundaries and divide land. T/F
True
If a survey requires more than one day to complete, a new page is started on the second day regardless of the number of blank spaces available. T/F
True
If the survey recorded is concerned aobut making incorrect entries, a format of using every other line is acceptable and creates a space to make corrections. T/F
True
It is an accepted practice to add dimensions between stations in the sketch of a taping traverse. T/F
True
Keeping the decimal points in a vertical line when entering data is a desirable trait in a set of field notes. T/F
True
Large survey projects may require multiple tabulation pages while only a single sketch page is completed. T/F
True
Making all calculations as the data is collected helps to reduce the number of errors. Errors can be identified and corrected before proceeding with the survey. T/F
True
Sketches are made to general proportions and are located in the right hand side of the field notebook pages. T/F
True
Some target rods are equipped with a sliding sight in order to make reading the target rod over long distances possible. The majority of agricultural target rods are self-reading and do not require a sliding sight. T/F
True
Survey notes should never be fudged to improve accuracy. T/F
True
Symbols are an acceptable method for listing the duties of each member of the survey party. T/F
True
The arrangement of data in a field note page for a taping exercise is often helpful to understand the data. T/F
True
The column headings are placed between the top two horizontal lines on the left page. T/F
True
The entries in a field notebook are typically printed as printing is generally easier to read. T/F
True
The quality of a survey is reflected in the quality of the field notes. T/F
True
Traditionally, hard pencils have been recommended for recording survey notes as they withstand damp weather and hard use better than graphite pencil lead or ink. The best pencils for surveying are 3H and 4H. T/F
True
Use a standard recommended form to comply with arrangment and to be consistent. T/F
True
Weather information is recorded and can affect the accuracy of the survey. T/F
True
When a sketch is drawn in a field notebook, a symbol indicating North (N) is included. T/F
True
When completing a set of taping field notes the sketch page should contain a sketch of the traverse made to general proportions. T/F
True
When conducting a taping exercise the survey crew should plan to tape both directions to obtain the most accurate measurements. T/F
True
When creating a sketch, indicate north (N) on the sketch page. T/F
True
When moving a tripod and instrument, carry the unit on your shoulder, with the instrument at the rear, to the new location. T/F
True
When taping, a survey team measures both directions to obtain accurate measurements. T/F
True
Backsight -
a reading taken on a point of known (or assumed) elevation
Foresight -
a reading taken on a point of unknown elevation
Perpendiculars may be created using surveying equipment. A perpendicular is _______ to a line.
a right angle
Traverse -
a series of connecting lines whose ends have been marked in a field, and whose lengths and direction have been determined from measurements, there are two types: open and closed
When defining a rectangle, all interal angles __________.
are right angles
If the target rod markings cannot be distinguished after adjusting the focus knob, the _____________.
distance to the target rod is too great
What do surveyors measure?
distance, angles, positions
Total station -
measures horizontal and vertical angles as well as horizontal and vertical distances
What are mistakes?
observed blunders caused by misunderstanding, carelessness, fatigue, miscommunication, poor judgement
When reading a self-reading target rod, the bottom of the black segments represent ___ values.
odd
Measuring distance using a wheel of known circumference is typically used in automobiles, motor cycles, and bicycles to register distance traveled. This same procedure when applied to surveying is called ___________.
odometry
When leveling a survey instrument both hands are used. The leveling screws are turned __________ to level the instrument.
one counterclockwise and one clockwise (opposite or towards each other)
The alternating black and white segments on a target rod represent _________.
one hundredth of a foot
When setting the tripod on uneven ground, such as the side of a hill, place _____________.
one leg on the uphill side and two legs downhill
Black numbers on the target rod represent __________.
one tenth of a foot
To level a surveying instrument the leveling screws must first be __________.
seated against the base plate
The process of leveling a survey instrument requires multiple steps. The leveling process is repeated over the leveling screws until ________.
the instrument indicates level through a 360 degree rotation
